The present invention relates to apparatus for manipulating rod-shaped articles which constitute or form part of smokers' products. More particularly, the invention relates to improvements in apparatus for changing the distance between pairs of coaxial rod-shaped articles, such as plain cigarettes.
In the manufacture of filter cigarettes and related smokers' products, pairs of coaxial plain cigarettes of unit length are moved sideways in the flutes of an assembly conveyor, and a filter rod section or mouthpiece of double unit length is placed between each pair of plain cigarettes. The thus obtained groups of three coaxial articles each are thereupon provided with adhesive-coated uniting bands which are rolled around the mouthpieces and the adjacent end portions of plain cigarettes to convert each group into a filter cigarette of double unit length. Each such cigarette is severed midway between its ends to yield two coaxial filter cigarettes of unit length.
Prior to insertion of filter mouthpieces, the distance between each pair of coaxial plain cigarettes of unit length must be increased so that the width of the resulting gap suffices for reception of a filter mouthpiece of double unit length. In accordance with the presently prevailing practice, plain cigarettes are moved apart by transferring them onto a conveyor system wherein the flute for one cigarette of each pair moves axially or substantially axially and away from the flute for the other cigarette of the same pair. Reference may be had to commonly owned U.S. Pat. No. 3,372,702 granted Mar. 12, 1968 to Bohn et al. which discloses an apparatus wherein the means for increasing the distance between successive pairs of coaxial plain cigarettes of unit length comprises four conical conveyors. Such apparatus are quite satisfactory; however, their space requirements are substantial and the number of component parts is large.